Electric-circuit closer.



E. M. McGRATH.

ELECTRIC cmc un CLOSER. APPLICATION FILED JAN. 8. I9I8.

Patented Feb. 25, 1919.

2 SHEETSSHEET l- E. M. McGRATI'L' I ELECTRIC CIRCUIT CLOSER. APPLICATIONFILED JAN. 8. I918.

Patented Feb. 25, 1919.

2 SHEETS-SHEET 2 Q /4 K I l UNITED STATES PATENT OFFICE.

EARL M. MCGRATH, or HELENA,I.MONTANA.

ELECTRIC-CIRCUIIT CLO'SER.

To all whom it may concern:

Be it known that I, EARL .MORRIS MCGRATH, a citizen of the UnitedStates, residing at Helena, in the county of Lewis and Clark and Stateof Montana, have invented certain new and useful Improvements inElectric-.

ments in electric, circuit closers where it is desired to shiftanelectric circuit so that it may be caused to passthrough a series'ofelectrically-operated devices, such as Incandescent lamps, so that thecurrent may flow through said devices either in series,,or in parallel,or in multiple groups, as may be desired.

My invention is especially intended to provide a circuit closer for usein controlling the headlights of automobiles, such as is described in myapplication filed November -30, 1917, Serial No. 204.614.

In order that the invention maybe more fully understood, it will beconvenient to refer briefly to such a system to which said inventionisespecially adapted, and then to describe in detail the construction ofthe parts constituting the present invention.

Reference is had to the accompanying drawings, in which similarreference symbols indicate similar parts throughout the several views,and in which Figure. 1 is a diagram showing the system with the circuitcloser shown diagrammatically and in the position for causing thecurrent to flow through the lamps in parallel.

Fig. 2 shows the other position of the circuit closer, in which thecurrent iscaused to flow through the lamps in series.

Fig. 3 is a detail perspective view showin the casing'containin thecircuit closer, an the plunger mounte therein.

Fig. 4 shows a central vertical section through the casing shown in Fig.3, parts be ing shown in elevation, and the plunger being in theposition for transmitting the current through the lamps in series.

Fig. 5 is a similar view, but showing the plunger in the positionfortransmitting the current through the lamps in multiple.

Fig. 6 shows a section along the line 66 of Fig. 4, and looking in thedirection of the arrows,

Specification of Letters Patent.

Application filed January 8, 1918. Serial N 0. 210,857.

Patented Feb.

Fig. 7 is a plan view of the insulating plug closing one end of thecircuit closer casing.

Fig. 8 shows a section along the line 88 of Fig. 7, and looking in thedirection of the arrows; and

Fig. 9 is a detail perspective view showin the circuit closerconnections as detachedfrom the casing.

Referring first to the diagram shown in Figs. 1 and 2, Arepresents amagneto generator; B represents the headlight switch; C and C representthe headlights; D represents the auxiliary switch or electric circuitcloser; and G represents the ground to which the various which, in thecaseof an automobile, is the -metallic framework of the machine.

The current flows from the generator A through the terminal 1 to. theheadlight swltch B, which is shown in the open position in Fig.1; butwhich, when closed, willtransmit the current to the conductor 2, whichhas two branches 3 and 3.

Q The current flows, when the parts are in the position shown in Fig. 1,in parallel through the lamps C as follows :from the conductor 2 throughthe conductor 3 and thelamp C and the conductor 4 to the terminal 5,brush 6, the terminal 7 and the conductor 8 to ground.

The current flows through the lamp C as follows: from the conductor 2through. the conductor 3 to the terminal 9, the brush 10, the terminal11, the conductor 12, the lamp C and the conductor 13 to ground.

When the parts are in the position shown in Fig. 2 the current flowsfrom the conductor4 to the terminal 5, as before, and passes to thebrush 6, but instead of going through the terminal 7, as shown in Fig.1, the current passes from the brush 6 through the conducting bar 14 tothe brush l0 and thence to. the terminal 11, whence it flows terminalsare connected,

as heretofore- In the position shown in Fig. 2, the terminals 7 and 9are cut out of circuit, as are also the conductors 3 and'8, so that thecurrent in this case will pass through the lamps in series. The brushes6 and 10 are insulated from each other, as shown at 15.

The circuit closing and breaking arrangement, shown diagrammatically inFigs. 1 and 2, is illustrated in detail in Figs. 3 to 9, in which 20represents a shell preferably cylindrical in form, having a flange orring 21 secured to the upper end thereof. Fixed in the lower end of thisshell is the insulating plug 22, which is cut out at the center, as at23, and is provided with an'upwardlyprojecting post 24 and a shorterupwardlyprojecting post 25, each as at 26 and 25 to facilitate thesecuring ofthe terminal wires 5, 7 9 and 11, which are preferably madein the form of a hairpin, one end of which passes through the outergrooves 26, and the other end passes through the inner grooves 26 andthe perforations 27 in said plug, and the ends of the wire forming theterminals are then twisted together and are connected to the conductors4, 8, 3 and 12, respectively.

The shorter post 25 is recessed, as at 25, see Fig. 8, and across therecessed portion is secured the conducting bar 14 shown in Figs. 4 and5.

Mounted in the upper end of the cylindrical casing 20 is a cylindricalcap 30, in which is mounted the insulating piece 15, to which thebrushes 6 and 10 are secured. These brushes are preferably in the formof a a hairpin, having outwardly curved contact ends as shown mostclearly in Figs. 5 and 6. This cylindrical cap is normally held in theraised positionshown in Fig. 4 by means of the spring 31, which engagesan arm 32 secured to, but preferably integral, with the said cap, theupper end of said spring epslot 34 in the cap 30.

When the cap 30 1s in the raised position shown in Fig. 4, the brushes 6and 10 are in the position shown in Fig. 2, and connect the lampsinseries; but when the cap 30 is pressed down to the position shown inFig. 5, the brushes 6 and 10 are in the position shown in Fig. 1, andWhile still remaining in contact with the terminals 5 and 11 have movedout of contact with the bar 14 and into contact with the terminals 7 anThus it will be seen that these brushes always remain in contact withthe terminals 5 and 11, but when in the raised position are connected bythe bar 14, and in the lowered position are out of contact with the bar14 but in contact with the terminals 7 and 9 on the short post 25 of theinsulating plugi122.

T e upper end of the cylinder 30 is closed by a cap piece 35 whichserves as a hearing or push button for the operator, and also by closingthe upper end of the cylinder 3) constitutes a neumatic dash-potarrangement by imprisoning the air in the circuit closer and tends toprevent any objectionable click when the cap 30 is pressed down. Thisaction of the imprisoned air is also supple,

mented by the resiliency of the spring 31.

The brushes 6 and 10 are made of springs of suflicient stiffness andresiliency to form of which is grooved,

, tube being rovided with always-a perfect electrical connection withthe corresponding contact members, in spite of the jolts and vibrationsto which the car is necessarily subjected in its normal use. Moreover,this stiffness of the spring brushes serves as a friction brake againstthe action of the spring 31, and thus prevents the sudden expulsion withresultant click of the plunger 30 when released from pressure bytheoperator.

Obviously the spring 31 should also be strong enough to returntheplunger to the initial position against such friction, when the plungeris released.

. The operation of the device will be fully understood by reference toFigs. 1 and 2 of the drawings,

parallel or in series, as the case may be. It will be seen that theplunger or cap is which show the plunger or cap in the lowered andraised positions, re-. spectively, for connecting-the lamps eitheralways automatically returned to the initial construction and in thecombination and arrangement of parts which could be used Withoutdeparting from the spirit of my invention; and I do not mean to limitthe invention to such details unless particularly pointed out in theclaims.

Having thus described my invention, what I claim and desire to secure byent of the United States is 1'. In an electric circuit closer, thecombination with two telescopic tubes, the inner a cap, of an insulatingplug mounted in the outer tube opposite said cap and carrying twoopposed pairs of contacts, onepair of contacts being shorter than theopposite pair, bar spaced away from said shorter pair of contacts andopposite to the upper end of the longer fpair of contacts, an isulatingblock carried by said inner tube, of a hair in connected to saidinsulating block and aving their free ends on one side adapted tocontinuously engage the longer pair of contacts carried by saidinsulating plug, and on their opposite side adapted to engage eithersaid conducting bar, or said shorter contacts, substantially asdescribed.

2. In an electric circuit closer, the combination with two telescopictubes, the inner tube being provided with a cap, of an insulating plugmounted in the outer tube 0p posite said cap and carrying two opposedpairs of contacts, one pair of contacts being shorter than the oppositepair, with a conducting bar spaced away from said shorter pair ofcontacts, an insulating block carried by said inner tube, and

a pair of resilient Letters Patwith a conducting 1 and a pair ofresilient brushes each substantially in the form of contacts hairpinconnected to said insulating block and having their free ends on'oneside adapted to continuously engage the longer air carried by saidinsulating p ug, and on their opposite side adapted to engage eithersaid conducting bar, or said shorter contacts, with a spring normallythe raised position, substantially as described.

3. In an electric circuit closer, the combination with two telescopictubes, the inner tube being provided with a cap, of an insu lating plugmounted inlthe outer tube opposite said cap and carrying two opposedpairs of contacts, one pair of contacts being shorter than the oppositepair, with a con-' ducting bar spaced away from saidshorter pair ofcontacts and end of the longer pair of-contacts, an insulating blockcarried by said inner tube, a pair of'resilient brushes connected. tosaid insulating block and having their 'free ends v on one side adaptedto' continuously engage the longer pair side to engage either saidshorter contacts, the inner tube being provided with a slot,

adapted to continuously enga pair of contacts carried by t of contactscan'ied'by the said insulating plug, and on their opposite saidconducting bar or a pin projecting from the outer tube through saidslot, and a spring having one end secured to said pin and the other endconnected to stantially as described.

4. In an electric circuitcloser, the combisaid inner tube, sub- 7 nationwith two telescopic tubes, the inner 'latingplug mounted in the outertube oppo-' site said cap and carrying two opposed pairs of contacts,one

tube being provided with a cap, of an insupair of contacts being shorterthan the opposite pair, with a conducting bar spaced away from saidshorter pair of contacts and opposite to the upper end of the longerpair of contacts, an insulating block carried by said inner tube, a pairof resilient brushes each substantially in the form of a hairpinconnected to said insulating block and having their free ends on oneside e the'longer opposite to the upperscribed. v v i I v In; anelectric circuit closer, 'the combisite said cap and the distendedposition,

c said inswengage either said conductin bar or said shorter contacts,the inner tu being provided with a slot, a pin projecting from the outertube through said slot, and a spring having one end secured to said pinand the other end connected to said inner tube, substantially asdescribed.

' 5. In an electric circuit closer, the combination with two telescopictubes, the inner tube being provided with a cap, of an insulating plugmounted in the outer tube opposite said cap and closingthe same, the twocylinders closedat opposite ends respectively forming a pneumaticdash-pot, contacts carried by said plug, ried by said inner tube andengaging said contacts, the inner tube being provided with a slot, a pinprojecting from the outer tube through said slot, and a spring havingone end's'ecuredto said pin and the other end connected to said innertube and adapted to automatically restore said inner tube to thedistended position, substantially as denation with two telescopic tubes,the inner tube being provided with a cap, of an insulating plug mountedin the outer tube oppothe outer walls thereof, and with perforationsnearthe center thereof, metal contact strips in the form of wires laid insaidouter grooves and passing through said perforations, and having thefree ends of each wire twisted together, resilient brushes carried vbysaid inner tube positioned to engage the contact strips carried by saidinsulating plug, the inner tube being provided with a slot, a pinprojecting from the outer tube through said slot, and a spring havingone [end secured to said' pin and the other end connected 'to said innertube and adapted togautomatically restore said inner tube tosubstantially as de scribed.

In testimony whereof, I aflix my signature.

EARL M. MoGRATH.

brushes carprovided with grooves in

